Support explicit header-only libraries
To date we have been using static libraries with no source files as
header-only libraries. Switch to using header_libs to make the user's
expectations clear, in case we need to differentiate the semantics of
static libraries and header-only libraries when we enable transitive
static library dependencies.
Test: mma -j external/llvm
Change-Id: I3ce16df11076b637bd192880e86ec9027738b9e7
diff --git a/cc/cc.go b/cc/cc.go
index 0ea4713..3fc694f 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -54,8 +54,9 @@
type Deps struct {
SharedLibs, LateSharedLibs []string
StaticLibs, LateStaticLibs, WholeStaticLibs []string
+ HeaderLibs []string
- ReexportSharedLibHeaders, ReexportStaticLibHeaders []string
+ ReexportSharedLibHeaders, ReexportStaticLibHeaders, ReexportHeaderLibHeaders []string
ObjFiles []string
@@ -221,6 +222,7 @@
staticExportDepTag = dependencyTag{name: "static", library: true, reexportFlags: true}
lateStaticDepTag = dependencyTag{name: "late static", library: true}
wholeStaticDepTag = dependencyTag{name: "whole static", library: true, reexportFlags: true}
+ headerDepTag = dependencyTag{name: "header", library: true, reexportFlags: true}
genSourceDepTag = dependencyTag{name: "gen source"}
genHeaderDepTag = dependencyTag{name: "gen header"}
genHeaderExportDepTag = dependencyTag{name: "gen header", reexportFlags: true}
@@ -556,6 +558,7 @@
deps.LateStaticLibs = lastUniqueElements(deps.LateStaticLibs)
deps.SharedLibs = lastUniqueElements(deps.SharedLibs)
deps.LateSharedLibs = lastUniqueElements(deps.LateSharedLibs)
+ deps.HeaderLibs = lastUniqueElements(deps.HeaderLibs)
for _, lib := range deps.ReexportSharedLibHeaders {
if !inList(lib, deps.SharedLibs) {
@@ -569,6 +572,12 @@
}
}
+ for _, lib := range deps.ReexportHeaderLibHeaders {
+ if !inList(lib, deps.HeaderLibs) {
+ ctx.PropertyErrorf("export_header_lib_headers", "Header library not in header_libs: '%s'", lib)
+ }
+ }
+
for _, gen := range deps.ReexportGeneratedHeaders {
if !inList(gen, deps.GeneratedHeaders) {
ctx.PropertyErrorf("export_generated_headers", "Generated header module not in generated_headers: '%s'", gen)
@@ -644,6 +653,8 @@
deps.LateSharedLibs, variantLateNdkLibs = rewriteNdkLibs(deps.LateSharedLibs)
}
+ actx.AddVariationDependencies(nil, headerDepTag, deps.HeaderLibs...)
+
actx.AddVariationDependencies([]blueprint.Variation{{"link", "static"}}, wholeStaticDepTag,
deps.WholeStaticLibs...)
@@ -910,6 +921,8 @@
ctx.AddMissingDependencies(missingDeps)
}
depPaths.WholeStaticLibObjs = depPaths.WholeStaticLibObjs.Append(staticLib.objs())
+ case headerDepTag:
+ // Nothing
case objDepTag:
depPaths.Objs.objFiles = append(depPaths.Objs.objFiles, linkFile.Path())
case crtBeginDepTag:
diff --git a/cc/library.go b/cc/library.go
index 5ba1a97..666c47a 100644
--- a/cc/library.go
+++ b/cc/library.go
@@ -90,6 +90,7 @@
android.RegisterModuleType("cc_library", libraryFactory)
android.RegisterModuleType("cc_library_host_static", libraryHostStaticFactory)
android.RegisterModuleType("cc_library_host_shared", libraryHostSharedFactory)
+ android.RegisterModuleType("cc_library_headers", libraryHeaderFactory)
}
// Module factory for combined static + shared libraries, device by default but with possible host
@@ -127,6 +128,13 @@
return module.Init()
}
+// Module factory for header-only libraries
+func libraryHeaderFactory() (blueprint.Module, []interface{}) {
+ module, library := NewLibrary(android.HostAndDeviceSupported)
+ library.HeaderOnly()
+ return module.Init()
+}
+
type flagExporter struct {
Properties FlagExporterProperties
@@ -271,6 +279,19 @@
}
func (library *libraryDecorator) compile(ctx ModuleContext, flags Flags, deps PathDeps) Objects {
+ if !library.buildShared() && !library.buildStatic() {
+ if len(library.baseCompiler.Properties.Srcs) > 0 {
+ ctx.PropertyErrorf("srcs", "cc_library_headers must not have any srcs")
+ }
+ if len(library.Properties.Static.Srcs) > 0 {
+ ctx.PropertyErrorf("static.srcs", "cc_library_headers must not have any srcs")
+ }
+ if len(library.Properties.Shared.Srcs) > 0 {
+ ctx.PropertyErrorf("shared.srcs", "cc_library_headers must not have any srcs")
+ }
+ return Objects{}
+ }
+
objs := library.baseCompiler.compile(ctx, flags, deps)
library.reuseObjects = objs
buildFlags := flagsToBuilderFlags(flags)
@@ -574,6 +595,11 @@
library.Properties.BuildStatic = false
}
+func (library *libraryDecorator) HeaderOnly() {
+ library.Properties.BuildShared = false
+ library.Properties.BuildStatic = false
+}
+
func NewLibrary(hod android.HostOrDeviceSupported) (*Module, *libraryDecorator) {
module := newModule(hod, android.MultilibBoth)
diff --git a/cc/linker.go b/cc/linker.go
index f4599e3..4619926 100644
--- a/cc/linker.go
+++ b/cc/linker.go
@@ -37,6 +37,9 @@
// list of modules that should be dynamically linked into this module.
Shared_libs []string `android:"arch_variant"`
+ // list of modules that should only provide headers for this module.
+ Header_libs []string `android:"arch_variant,variant_prepend"`
+
// list of module-specific flags that will be used for all link steps
Ldflags []string `android:"arch_variant"`
@@ -69,6 +72,10 @@
// present in static_libs.
Export_static_lib_headers []string `android:"arch_variant"`
+ // list of header libraries to re-export include directories from. Entries must be
+ // present in header_libs.
+ Export_header_lib_headers []string `android:"arch_variant"`
+
// list of generated headers to re-export include directories from. Entries must be
// present in generated_headers.
Export_generated_headers []string `android:"arch_variant"`
@@ -112,9 +119,11 @@
func (linker *baseLinker) linkerDeps(ctx BaseModuleContext, deps Deps) Deps {
deps.WholeStaticLibs = append(deps.WholeStaticLibs, linker.Properties.Whole_static_libs...)
+ deps.HeaderLibs = append(deps.HeaderLibs, linker.Properties.Header_libs...)
deps.StaticLibs = append(deps.StaticLibs, linker.Properties.Static_libs...)
deps.SharedLibs = append(deps.SharedLibs, linker.Properties.Shared_libs...)
+ deps.ReexportHeaderLibHeaders = append(deps.ReexportHeaderLibHeaders, linker.Properties.Export_header_lib_headers...)
deps.ReexportStaticLibHeaders = append(deps.ReexportStaticLibHeaders, linker.Properties.Export_static_lib_headers...)
deps.ReexportSharedLibHeaders = append(deps.ReexportSharedLibHeaders, linker.Properties.Export_shared_lib_headers...)
deps.ReexportGeneratedHeaders = append(deps.ReexportGeneratedHeaders, linker.Properties.Export_generated_headers...)